Depth compensator valve

ABSTRACT

A pressure regulator system for controlling pressure differential between a buoyancy sphere and the ambient water pressure during descent of the buoyancy sphere employs a control valve arrangement. The body of the valve arrangement is mounted integrally on the buoyancy sphere and communicates with the interior. A diaphragm control valve and pintle control the flow of gas producing fuel so as to regulate the amount of gas passing to the interior of the buoyancy sphere to thereby maintain a predetermined pressure differential. The valve mechanism also includes flushing means to cleanse portions of the interior of corrosive salt water and other materials admitted during operation.

United States Patent [1 1 Strickland Sept. 11, 1973 DEPTH COMPENSATORVALVE [75] Inventor: Alvah T. Strickland, Kailua, Hawaii [73] Assignee:The United States of America as represented by the Secretary of theNavy, Washington, DC.

[22] Filed: May 26, 1972 [21] Appl. No.: 257,087

[52] U.S. Cl 114/16 E [51] Int. Cl...l B63g 8/24 [58] Field of Search114/16 R, 16 E, 50;

[56] References Cited UNITED STATES PATENTS 3,538,930 'll/l970 K'owalskil37/8l Primary Examiner-Duane A. Reger Assistant Examiner-Galen L.Barefoot Attorney-Richard S. Sciascia et al.

[57] ABSTRACT A pressure regulator system for controlling pressuredifferential between a buoyancy sphere and the ambient water pressureduring descent of the buoyancy sphere employs a control valvearrangement. The body of the valve arrangement is mounted integrally onthe buoyancy sphere and communicates with the interior. A diaphragmcontrol valve and pintle control the flow of gas producing fuel so as toregulate the amount of gas passing to the interior of the buoyancysphere to thereby maintain a predetermined pressure differential. Thevalve mechanism also includes flushing means to cleanse portions of theinterior of corrosive salt water and other materials admitted duringoperation.

9 Claims, 3 Drawing Figures DEPTH COMPENSATOR VALVE STATEMENT OFGOVERNMENT INTEREST The invention described herein may be manufacturedand used by or for the Government of the United States of America forgovernmental purposes without the payment of any royalties thereon ortherefor.

FIELD OF THE INVENTION This invention pertains to the field of navalarchitecture and marine engineering. More particularly, this inventionpertains to the field of submersible marine engineering. Equipment towhich the invention is directed is the buoyancy transport vehicleequipment used by untethered underwater divers. In still greaterparticularity, the invention pertains to a pressure regulation system tocontrol the pressure differential between the buoyancy sphere portion ofsuch buoyant transport vehicles and the ambient water pressure duringdescent of the buoyant transport vehicle.

DESCRIPTION OF THE PRIOR ART For centuries, man has been interested inretrieving objects from the floor of the sea. In depths too great to bereached by surface probes and grappling means, divers have been theprimary means for accomplishing these underwater retrieval tasks. Untilcomparatively modern times, the limitation on man s ability to recoversuch objects as he may desire from the floor of the ocean has been hisability to remain submerged for sufficiently long periodsof time. Modernadvances in diving suits, breathing systems, and other life supportapparatus has greatly extended the length of time which man may remainbelow the surface. As in other arts, these modern advances have onlyhighlighted further limitations on mans ability to control his newenvironment. I

In particular, the primary motive power heretofore available to a workeremployed beneath the surface of the water has been his ownmuscle power.In order to raise objects heavier than he has been able to lift andcarry while swimming, man has had to depend upon a lifting arrangementcontrolled from the surface. Because of the difficulty in communicationbetween the ocean floor and the surface as well as certain inherentengineering limitations concerned with the air water interface, theseprior systems have left a great deal to be desired. Only by. providingdivers with mechanical, labor-saving lifting devices and similar aidsfor transporting heavy objects could the usefulness of the modernadvances in diving be fully realized.

Recent innovationsin this area included small salvage pontoons whichmay, be placed on objectsto be returned tothe surface when inflated bythe divers.

However, the ultimate desire and recent-realization has been theprovisionof a buoyant transportvehicle which could be regulated inbuoyancy and propulsive forces by. the diver to transport a load to adesired location in the ocean or on the ocean surface. i

For the effective operation of such buoyant transport siderable troubleis the pressure'exerted on the buoyant lifting chamber by submergence ofthe vehicle. In prior art arrangements, the pressure'on the buoyancysphere was manually controlled. As a result of divers b'econiingpreoccupied with other tasks during subrnergenc e or with inability tooperate the controls in a proper sequence, damage to the buoyancy spherewas sometimes encountered. Of course, a certain amount of risk or dangerto the divers also accompanies any damage or serious disruption of theintegrity of the buoyancy sphere. These hazards are very undesirable andtheir minimizationis, quite naturally, a goal of all engineeringdevelopments in this field.

For a variety of reasons, previous attempts to eliminate the manualoperation of the pressure control for the buoyancy transport vehiclehave been only marginally successful. Various regulator mechanisms havebeen tried but only with limited success. For example, scuba breathingregulators were tried to inject into the buoyancy sphere gas under highpressure so as to equalize the pressure differential during descent.However, a source of gas of sufficient size to fill the buoyancy chamberat great depths is impractical from a standpoint of size, as well asother considerations.

The most successful approach to the problem has been to generate the gasfrom a suitable fuel in areaction chamber and inject the gas into theinterior of the buoyancy sphere and thereby equalize the pressure.However, the regulation of the flow of fuel to the gas generator hascaused problems similar to'those mentioned above in connection with theintroduction of gas under pressure from an external source. Knownregulator valves to accomplish this purpose automatically have beenmechanically too fragile for the arduous working conditions imposed inunderwater applications. Also, the corrosive action anddeposits carriedby the seawater causes premature failure of valves of knownmanufacturing type.

STATEMENT OF THE OBJECTS OF THE INVENTION buoyancy control systememploying a valve having high mechanical strength.

Another object of this invention is to provide a buoyancy control systememploying an. automatic valve having provisions for minimizingthecorrosive effects of seawater. j

Still another object of this invention is to provide a buoyancy controlsystem incorporating a regulation valve which will regulate a gasproducing fuel flow to a gasgenerator so as to alter the pressure withina buoyancy system.

Stillanother object of this invention is to provide an improveddiaphragm type valve capable of withstanda ing the sustained operationbeneath the surface of the sea.

' Theseand other objects of the invention will become more'readilyapparent from the ensuingspecification whentaken with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of amobile transport vehicle employing the buoyancy control system of theinvention;

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, thebuoyancy transport vehicle, indicated generally at 11, is shown beingoperated by a diver-operator 12 moving an object 13. Object 13 isaffixed to buoyancy transport vehicle 11 by means of suitable tackle andother conventional purchase, such as hook 14. The principal component ofbuoyancy transport vehicle 11 is a suitable buoyancy or lifting spherel5. Buoyancy sphere 15 is surrounded by an appropriate framework 16which protects the buoyancy sphere and other apparatus mounted onbuoyancy transport vehicle 11 from contact with the sea bottom or otherobjects. The buoyancy transport vehicle 11 is moved by means of suitablepropulsion units indicated generally at 17. In the embodiment shown,there are two horizontally aimed thruster units and two vertically aimedunits. Of course, other combinations and arrangements of conventionalpropulsion means may be employed if desired. The control of the buoyancytransport vehicle 11 is effected by diver-operator 12 by means of asuitable control console 18. Any suitable control console arrangementmay be used but that disclosed in the inventors copending applicationSer. No. 237,304 filed Mar. 23, 1972 for Buoyancy Transport VehicleControl Console, has proven successful.

As shown, framework 16 supports other equipment which forms part of thebuoyancy transport vehicle. Of particular note is a lower pod 19 whichcontains a source of gas producing fuel. The particular fuel employeddepends upon the type of gas generator employed and other parameterswhich may be varied to suit the particular application. However, forpurposes of completeness and by way of explanation, it should be notedthat hydrazine has been used successfully in the device of theinvention. The hydrazine fuel supply is connected to the gas generatorby suitable fluid conduit means 21. Referring to FIG. 2, a fragmentalview of the buoyancy sphere 15 shows the arrangement by which the valvecontrol system according to the invention is mounted thereon. As shown,the valve, indicated generally at 22, extends outwardly from the surfaceof buoyancy sphere 15. Of course, if desired, the exposed valve body 22and adjacent conduit 21 may be enclosed by a suitable shielding box soas to protect it from accidental impact. As will become more clearsubsequently, if such a protective cover is employed it must be free tocommunicate with the ambient pressure environment in which the buoyancytransport vehicle operates.

As shown, the valve 22 comprises two major portions. A valve bodyportion 23 is outermost in relation to buoyancy sphere l5. Ahousingportion 24 supports the valve body portion 23 and emerges from theinterior of buoyancy sphere 15. Housing portion 24 may be secured tobuoyancy sphere 15 by any of several suitable means. For example, thevalve 22 may be integrally formed with sphere 15 or, as illustrated, besecured by a plurality of threaded fasteners 25.

After passing through the depth compensator valve, the hydrazine fuelgoes through a check valve, not shown, and then into a suitable gasgenerator 26 where the fuel is discomposed to form hot gases. Thesegases pass through a heat exchanger, not shown, and another check valve,not shown, before being injected into buoyancy sphere 15. The gasgenerator may be one of several available types and, if desired, may belocated within a suitable housing to afford more protection than thatprovided by the illustrated position, which is somewhat exposed.

Referring now to FIG. 3, the internal construction of the regulatingvalve according to the invention will be described. A suitablyconfigured cap member 27 is secured to housing portion 24 by means ofthreaded fasteners 25. A seal is provided between the housing portion 24of valve 22 and the wall of buoyancy sphere 15 by means of a suitablegasket 28. A flexible diaphragm 29 is positioned between cap member 27and housing portion 24 and the entire assembly of housing portion 24 andcap member 27, gasket 28 and diaphragm 29 are held into a unitaryassembly by means of threaded fasteners 25. If desired, otherconstructional arrangements may be employed rather than use threadedfasteners 25, for example, cap portion 27 may be integrally formed intobuoyancy sphere 15 and housing portion 24 may be bodily threadedthereon. However, the illustrated arrangement permits independentservicing and replacement of the valve system.

As may be seen, diaphragm 29 divides the internal void between capmember 27 and housing portion 24 into two compartments. A suitablyconfigured backing plate 31 is placed adjacent diaphragm 29 in thehousing compartment and a similar backing plate 32 is placed on theother side of diaphragm 29 so as to be in the cap compartment. Besidesperforming their well understood function of stiffening diaphragm 29 soas to confine the flexure thereof to the outer circumference thereof,backing plate 32 provides an additional function of limiting theexcursion of diaphragm 29 toward cap member 27. Backing plates 31 and 32are held against diaphragm 29 so as to form a unitary constructiontherewith by means of a threaded stud 33 and suitable fastenerscooperating therewith.

A vent 34 is provided in cap member 27 so as to provide communicationbetween the cap side of diaphragm 29 and the interior of buoyancy sphere15. Similarly, a vent 35 provides access between the ambient wateroutside buoyancy sphere l5 and diaphragm 29 on the housing portion sidethereof. As may be readily understood, the pressure differential betweenthe interior of buoyancy sphere l5 and the ambient water surrounding itmove diaphragm 29 either toward cap 27 or toward the housing portion 24in dependence upon which pressure is the greater. It is for this reasonthat any protective cover surrounding'valve 22 should have fluid accessto-the ambient fluid atmosphere surrounding buoyancy sphere 15.

Threaded shaft 33 on the end closest to valve body portion 23 supports asuitably configured pintle means 36. At the opposite end of pintle 36 aneck portion 37 positions a valve seal 38 against a valve seat 39integrally formed with valve body portion 23. Neck portion 37 preventspintle 36 from obstructing fluid flow when the valve seal 38 is raisedoff valve seat 39 in the well understood fashion. A fluid tight seal ismade about pintle 36 by means of a gland 41 which may be threadedablyreceived into valve body portion 23 or, if desired, simply retained byvalve body portion 23 by means of a cooperating shoulder on valvehousing portion 24. If desired, the fluid tight seal may be improvedwith the use ofa suitable packing means such as O-ring 42 for example.Although providing a fluid tight seal, gland 41 and O-ring 42 permitpintle 36 to reciprocate and thereby follow the motion of diaphragm 29.

In the absence of pressure differential between the interior of buoyancysphere and the ambient surroundings, pintle 36 is biased so as to seatvalve seal 38 on valve seat 39 by means of a biasing spring 43. Biasingspring 43 exerts its biasing force against a washer 44 which is held topintle 36 by means of a suitable clip 45. The size and flexure ofbiasing spring 43 may be chosen so as to provide a predetermined bias onpintle 36 so as to correspond to a desired pressure differential atwhich the valve cracks open. In operative examples of the invention, aone pound per square inch differential between ambient sea pressure andinternal buoyancy sphere pressure has been successfully maintained.

it will be observed that, in addition to vent 35, a plurality of vents46 are provided in housing portion 24 of valve 22. Although these ventsalso provide pressure access from the ambient atmosphere to diaphragm29, they serve another valuable and important function in the system ofthe invention. As previously noted, valve mechanisms used in the arduoussurroundings of underwater marine engineering applications frequentlysuffer premature failures due to accumulations of mineral deposits andcorrosive action of the seawater. Vents 46 effectively prevent thisfailure from occurring in the device of the invention by affording anexhaust vent permitting the valve of the invention to be flushed withfresh water after each use in a salt water environment. Thus, when thebuoyancy transport vehicle 11 is taken aboard its service ship, a jet offresh water may be intorduced through vent andflood the chamber formedbetween diaphragm 29 and actuator portion 24 and pass along the pintle36 thereby cleansing spring 43 and exhausting through vents 46. Thispreventive maintenance permits the device to be deployed many timesbefore valve 22 must be disassembled and inspected. This saving ofoperational time is of great importance when one considers the limitedcrew and working space aboard ocean vessels.

Although the foregoing description is sufficient for one skilled in themarine engineering arts to make and use the invention, the inventionwill be more readily understood with reference to the following mode ofoperation.

MODE OF OPERATION The successful operation of the device providesautomatic pressure equalization between buoyancy sphere 15 and theambient environment during periods of descent. As buoyancy transportvehicle 11 is submerged beneath-the surface of the water, the externalpressure raises with relation to the interior of buoyancy sphere 15.When this pressure exceeds the interior pressure by the predeterminedamount provided by biasing spring 43, the ambient pressure exerted ondiaphragm 29 through vents 35 and 46 press diaphragm 29 inwardly. Theexcursion of diaphragm 29 is limited by the backing plate 32 contactingthe wall of cap member 27. This limitation affords protection fordiaphragm 29.

With diaphragm 29 in its innermost position, pintle '36 is drawn towardthe interior of buoyancy sphere 15.

This axial movement of pintle 36 raises valve seal 38 from valve seat39. in this position, a fluid passage through the valve body portion 23is established and suitable fuel flows from the lower pod fuel tank 19through fluid conduit 21 to the gas generator, after which the gas isinjected into the buoyancy sphere 15. Of course, the gas injected intothe buoyancy sphere l5 raises the pressure therein until it equals theambient pressure. When this condition has been obtained, bias-- ingspring 43 restores pintle 36 to its outward position thereby forcingvalve seal 38 against valve seat 39. in this position, the flow of fuelthrough the valve body is interrupted and the manufacture of gas withinthe gas generator ceases.

As a result of this regulatory action, a nearly uniform pressuredifferential is caused to exist between the interior of buoyancy spherel5 and its ambient environment during periods of descent. Thisregulation provides the desired control and frees the diver-operator 12to focus his attention and apply his efforts to other tasks.

The foregoing description taken together with the appended claims isseen to constitute a meritorous advance in the art which was unobviousto those skilled in the marine engineering and naval architecture artsnot having the benefit of these teachings. Further, the device of theinvention meets the aforestated objects of invention and generallyconstitutes a meritorous advance in the arts.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings, and, it is thereforeunderstood that within the scope of the disclosed inventive concept, theinvention may be practiced otherwise than specifically described.

What is claimed is:

1. In a buoyancy transport vehicle having a buoyancy sphere forproviding lifting buoyancy for objects attached to said vehicle, abuoyancy regulation system comprising:

a source of fuel under pressure;

a gas generator effectively joined to said buoyancy sphere for providingbuoying gas therefor;

fluid conduit means connected between said source of fuel under pressureand said gas generator for providing a passage therebetween;

valve meanseffectively connected in said fluid conduit means forregulating the fuel flow through said fluid conduit means, said valvemeans including:

a valve housing connected to the buoyancy sphere and having a firstpassage effectively connecting the interior of the valve housing to theinterior of the buoyancy sphere and a second passage means forconnecting the valve housing to the ambient fluid surrounding thebuoyancy sphere, flexible diaphragm within said valve housing andconstructed to divide said valve housing into two compartments, onecompartment being open to the interior of the buoyancy sphere via saidfirst passage and theother compartment being open to the pressure of theambient seawater environment via said second passage means;

a valve seat made integral with said valve housing and effectivelyconnected to said fluid conduit means and shaped to provide a passageorifice in fluid communication with said fluid conduit means;

a pintle reciprocally mounted in said valve housing and formed to openand close the fluid passage provided by said valve seat and mechanicallyconnected to said diaphragm to be reciprocally displaced thereby; and

resilient means biasing said pintle to a closed or seated position withrespect to said valve seat and yieldable to permit said pintle to assumean open position with respect to said valve seat upon the pressure inthe ambient environment exceeding the force provided by the resilientbiasing means and the pressure within said buoyant sphere.

2. A buoyancy regulation system according to claim 1 wherein said valvehousing includes:

a regulator portion having an enlarged end configured to receive saidflexible diaphragm in a hollow recess therein;

a cap portion fitting over the hollow recess of said regulator portionfor retention thereon so as to close the end thereof and cooperate withsaid flexible diaphragm to form said one compartment therewith; and

a valve body portion attached to said regulator portion for receivingsaid fluid conduit means and containing said valve seat therein.

3. A buoyancy regulation system according to claim 2 in which said valvehousing is attached to said buoyancy sphere with the cap portion and theenlarged end of said regulator portion within said buoyancy sphere andthe remainder of the regulator portion together with the valve bodyportion extending from said buoyancy sphere.

4. A buoyancy regulation system according to claim 7 3 furtherincluding:

a gasket positioned between the enlarged end of said regulator portionof said valve housing and the inner surface of buoyancy sphere forproviding a high-pressure gas-tight seal therebetween; and

fastening means cooperatively engaging said cap portion, the enlargedend of said regulator portion, said gasket, and said buoyancy sphere anddrawing said engaged elements together for ensuring a gas tightmechanical joint between said valve housing and said buoyancy sphere.

5. A buoyancy regulation system according to claim 4 further including:

a first backing plate secured to said flexible diaphragm on one sidethereof so as to be within said one compartment which is open to theinterior of said buoyancy chamber; and v a second backing plate securedto the other side of said flexible diaphragm opposite to said firstbacking plate, so that the flexure of said flexible. diaphragm inresponse to pressure difference may be controlled within predeterminedlimits.

6. A buoyancy regulation system according to claim 5 wherein the backingplates have a thickness selected to cooperate with the interior of theaforesaid valve body means so as to limit flexure movement of theaforesaid flexible diaphragm.

7. A buoyancy regulation system according to claim 6 including:

threaded shaft means effectively attached to said pintle means and tosaid flexible diaphragm so as to extend through the regulator portion ofsaid valve body for movement of said pintle means with said' flexiblediaphragm; and

valve seal means carried by said pintle means to cooperate with theaforesaid valve seat for opening and closing the fluid passagetherethrough in response to movement of said flexible diaphragm.

8. A buoyancy system according to claim 7 in which said pintle has asmaller cross section in the vicinity of said valve seal means forfacilitating the fluid flow.

9. A buoyancy system according to claim 1 including fluid passage ventsin the regulator portion of said valve body communicating between theinterior and exterior thereof to permit the washing of the interior ofthe valve with fresh water without disassembly of the valve.

1. In a buoyancy transport vehicle having a buoyancy sphere for providing lifting buoyancy for objects attached to said vehicle, a buoyancy regulation system comprising: a source of fuel under pressure; a gas generator effectively joined to said buoyancy sphere for providing buoying gas therefor; fluid conduit means connected between said source of fuel under pressure and said gas generator for proViding a passage therebetween; valve means effectively connected in said fluid conduit means for regulating the fuel flow through said fluid conduit means, said valve means including: a valve housing connected to the buoyancy sphere and having a first passage effectively connecting the interior of the valve housing to the interior of the buoyancy sphere and a second passage means for connecting the valve housing to the ambient fluid surrounding the buoyancy sphere, a flexible diaphragm within said valve housing and constructed to divide said valve housing into two compartments, one compartment being open to the interior of the buoyancy sphere via said first passage and the other compartment being open to the pressure of the ambient seawater environment via said second passage means; a valve seat made integral with said valve housing and effectively connected to said fluid conduit means and shaped to provide a passage orifice in fluid communication with said fluid conduit means; a pintle reciprocally mounted in said valve housing and formed to open and close the fluid passage provided by said valve seat and mechanically connected to said diaphragm to be reciprocally displaced thereby; and resilient means biasing said pintle to a closed or seated position with respect to said valve seat and yieldable to permit said pintle to assume an open position with respect to said valve seat upon the pressure in the ambient environment exceeding the force provided by the resilient biasing means and the pressure within said buoyant sphere.
 2. A buoyancy regulation system according to claim 1 wherein said valve housing includes: a regulator portion having an enlarged end configured to receive said flexible diaphragm in a hollow recess therein; a cap portion fitting over the hollow recess of said regulator portion for retention thereon so as to close the end thereof and cooperate with said flexible diaphragm to form said one compartment therewith; and a valve body portion attached to said regulator portion for receiving said fluid conduit means and containing said valve seat therein.
 3. A buoyancy regulation system according to claim 2 in which said valve housing is attached to said buoyancy sphere with the cap portion and the enlarged end of said regulator portion within said buoyancy sphere and the remainder of the regulator portion together with the valve body portion extending from said buoyancy sphere.
 4. A buoyancy regulation system according to claim 3 further including: a gasket positioned between the enlarged end of said regulator portion of said valve housing and the inner surface of buoyancy sphere for providing a high-pressure gas-tight seal therebetween; and fastening means cooperatively engaging said cap portion, the enlarged end of said regulator portion, said gasket, and said buoyancy sphere and drawing said engaged elements together for ensuring a gas tight mechanical joint between said valve housing and said buoyancy sphere.
 5. A buoyancy regulation system according to claim 4 further including: a first backing plate secured to said flexible diaphragm on one side thereof so as to be within said one compartment which is open to the interior of said buoyancy chamber; and a second backing plate secured to the other side of said flexible diaphragm opposite to said first backing plate, so that the flexure of said flexible diaphragm in response to pressure difference may be controlled within predetermined limits.
 6. A buoyancy regulation system according to claim 5 wherein the backing plates have a thickness selected to cooperate with the interior of the aforesaid valve body means so as to limit flexure movement of the aforesaid flexible diaphragm.
 7. A buoyancy regulation system according to claim 6 including: threaded shaft means effectively attached to said pintle means and to said flexible diaphragm so as to extend through the regulator portion of said valve body for movement of said pintlE means with said flexible diaphragm; and valve seal means carried by said pintle means to cooperate with the aforesaid valve seat for opening and closing the fluid passage therethrough in response to movement of said flexible diaphragm.
 8. A buoyancy system according to claim 7 in which said pintle has a smaller cross section in the vicinity of said valve seal means for facilitating the fluid flow.
 9. A buoyancy system according to claim 1 including fluid passage vents in the regulator portion of said valve body communicating between the interior and exterior thereof to permit the washing of the interior of the valve with fresh water without disassembly of the valve. 